1. Field of the Invention
The present invention relates in general to a system for laying masonry blocks and, more particularly, to a system and its components for laying masonry blocks in multiple-block units.
2. Background Art
Systems for hoisting and laying masonry and other building block have been known in the art for years. Some of these systems have incorporated various block hoisting devices. In particular, early block hoisting devices typically operated by placing one block at a time, by hand or via a mechanical block gripping jaw, onto a previously mortared row of blocks. By limiting the capacity of the device to one block at a time, a hoist system could achieve block placement accuracy, and eliminate the inconvenience and difficulties caused by heavy and bulky multiple block loads. At the same time, however, single-block hoists made the block laying process more time consuming and inefficient. Specifically, not only did such devices mandate a large number of individual block hoisting and laying steps, but such devices also required each block to be mortared after positioning in or on a wall.
Accordingly, hoisting devices were developed to raise, lower and even transport concrete and other building blocks in multiple block units with the use of an overhead hoist. A number of these multiple block hoisting devices consist of lifting tongs, which utilize a scissors-type clamping mechanism, and an underlying block support. While such devices help bear the weight of the blocks, the underlying supports prevent placement of the blocks onto a previously mortared row. Moreover, underlying block supports also limit the ability of the hoist to fit under blocks already positioned on a flat surface, such as a conveyor belt.
Still other of these multiple block hoisting devices include outer clamping jaws extending from a beam to secure the outermost blocks of a multiple block unit. In particular, upon lifting of such hoisting devices, the weight of the blocks prompts the clamping jaws to exert a force inwardly on blocks. Inasmuch as each block is in frictional engagement with an adjacent block, the blocks may be raised and transported in multiple block units. The beam often assists in distributing the weight of the blocks.
While such hoisting devices have worked well to increase block laying efficiency, they are limited by not only the weight of the individual blocks, but also by the number of blocks being lifted. Specifically, although the clamping jaw generally exert an inward clamping force on the outer blocks of the multiple block row, that clamping force diminishes toward the inner-most blocks in the multiple block unit. Thus, the block-to-block friction will not support particularly heavy block loads or long chains of blocks, thus resulting in block fallout or misalignment. Moreover, to the extent that such devices rely on block-to-block friction to maintain the blocks in a multiple block unit, creation of mortar joints between the blocks before hoisting is likewise made difficult.
Moreover, the outer clamping jaws tend to interfere with placement of the multiple block unit in a constrained area. Specifically, the clamping jaws prevent a multiple block unit from being positioned on top of a previously mortared row of blocks when placement must be adjacent to any other blocks. Likewise, the clamping jaws prevent placement of the multiple block unit in any position with a higher wall or other structure adjacent to the block placement target area.
Block hoisting and laying systems have also included devices for applying mortar to a row of blocks or bricks. Mortar laying devices typically include a guide to maintain alignment of the device over a row of blocks, and a mortar applicator for applying a coat of mortar to the top surface of the block row. In particular, the applicator is generally a chute or other opening to permit the flow of mortar therefrom, over the entire top surface of the blocks or bricks. The thickness of the mortar layer in these devices is typically controlled by the size of the applicator opening, the viscosity of the mortar, and/or the rate of movement of the mortar applying device over the block surface.
While these and other mortar laying devices have worked well when used in association with blocks or bricks without inner cavities, they have failed to provide for selectively limiting mortar application to certain regions of the block or brick surface. In particular, it is desirable to control the flow of mortar from the mortar applicator to avoid applying mortar into void regions, such as block cavities, where serves no purpose.
Accordingly, it is a goal in the art to provide a multiple block laying system which incorporates a multiple block hoist apparatus capable of handling any number of blocks, independent of block size, shape and weight. Moreover, it is also desirous to provide a block hoist apparatus which grips the inside of the block cavities to avoid obstacles or impediments to placing a multiple block unit on a desired target area. Likewise, it is a goal to provide a block hoist which exerts a gripping force either directly to or proximate to each block, to ensure that the multiple block unit remains integral and aligned during raising, lowering and transportation thereof.
Moreover, it is a goal in the art to provide a multiple block laying system which incorporates a mortar laying apparatus that selectively controls the dispensing of mortar onto the top surface of a row of blocksxe2x80x94to not only facilitate selective application of mortar onto any top surface configuration, but to also substantially limit application of mortar into inner cavities of blocks.
The present invention is directed to a system and method for laying masonry blocks in multiple block units. The system comprises a mortar injection device, a block hoist apparatus and a mortar applying apparatus. The mortar injection device includes a mortar feed, mortar dispensing chutes, sliding shut-off gates and a vibrating block tamper. In a preferred embodiment, the mortar feed comprises a pressure pump for delivering mortar to the dispensing chutes. In another preferred embodiment, the mortar feed comprises a motor driven auger.
The mortar dispensing chutes are positioned to inject mortar into gaps between adjacent blocks in the multiple block unit, to create a mortar joint between each block. Each chute is preferably equipped with a sliding shut-off gate to control the flow of mortar from the dispensing chutes.
In one preferred embodiment, the block tamper comprises a vibratory roller positioned at the end of the mortar injection device, and facilitates substantially uniform settling of the mortar in the block gaps. In another preferred embodiment, the block tamper comprises a series of vibratory pistons positioned between each mortar dispensing chute and preferably aligned with the block gap spacing in a multiple block unit.
The block hoist apparatus includes a mechanical hoist, a hoist transmission member, a weight distribution beam, gripping arms pivotally attached to the weight distribution beam, major gripping members and minor gripping members. The mechanical hoist raises and lowers a multiple block unit, and preferably moves laterally for displacement of the multiple block unit.
The hoist transmission member connects the hoist to the weight distribution beam. In a preferred embodiment, the hoist transmission member comprises cables extending from the mechanical hoist to hooks associated with the weight distribution beam.
At a first end, the gripping arms are pivotally attached to the weight distribution beam, and preferably extend downwardly at an angle therefrom. In a preferred embodiment, the gripping arms are attached to a swivel joint associated with the weight distribution beam. The swivel joint is preferably mounted in a slot in the weight distribution beam, to allow slidable movement of the gripping arms relative to the weight distribution beam for minor adjustments in gripper arm positioning.
At a second end, the gripping arms are associated with major gripping members, which are mounted on the gripper mounting bar. In a preferred embodiment, the major gripping members are pivotally mounted on a float which is slidable in a slot in the gripper mounting bar. In another preferred embodiment, the float includes ports for mounting the major gripping members in different positions to accommodate different block sizes and configurations.
In yet another preferred embodiment, the major gripping members are pivotally mounted directly to the gripper mounting bar. It is likewise contemplated that the gripper mounting bar includes a series of apertures for mounting the major gripping members in adjustable positions relative to the gripper mounting bar.
Minor gripping members are also mounted to the gripper mounting bar. Each minor gripping member opposes and cooperates with a corresponding major gripping member, and is distally spaced from that opposing major gripping member. In one preferred embodiment, each pair of opposing major and minor gripping members are pivotally attached to the float, which is slidably adjustable in the slot in the gripper mounting bar. In another preferred embodiment, each pair of major and minor gripping members are mounted directly to the gripper mounting bar. In either case, it is contemplated that the major and minor gripping members may be adjusted along the length of the gripper mounting bar.
Each of the major and minor gripping members preferably includes a gripping face with grip enhancer. In a preferred embodiment, the grip enhancer includes a claw at the bottom of the major gripping members. In another preferred embodiment, the grip enhancer includes spikes, protrusions or corrugations on the gripping face.
Each of the major and minor gripping members are positionable into different block cavities and cooperate, upon lifting of the weight distribution beam by the mechanical hoist, to exert a clamping force along an interior portion of the blocks to retain the blocks in alignment for raising and lowering of the multiple block unit.
In another preferred embodiment, the major and minor gripping members are associated with either end of a telescoping gripper mounting bar. Preferably, the major gripping members are associated with an outer telescoping member, while the minor gripping members are associated with an inner telescoping member. The inner and outer telescoping members are adjustable relative to one another to alter the distance between the gripping surfaces on the respective major and minor gripping members, and may be locked before lifting of the apparatus.
In yet another embodiment, the gripping arms all extend downward from the weight distribution beam at substantially the same angle. Thus, each gripping arm, major gripping member and minor gripping member unit is oriented in substantially the same direction. Lifting of the weight distribution beam still transforms each gripping arm into a lever arm, and creates a clamping force along the interior portion of the inner cavity of the blocks positioned between each set of opposing major and minor gripping members.
In still another preferred embodiment, the block hoist apparatus includes a weight distribution beam, a gripper mounting bar, a first major gripping member, a second major gripping member, a first series of minor gripping members, a second series of minor gripping members, and first and second connecting rails. Each major gripping member is attached to not only the gripper mounting bar, but also to the respective first and second connecting rails. Likewise, each first series and second series of minor gripping members is likewise connected to both the gripper mounting bar and the respective first and second connecting rails. Preferably, the first and second series of gripping members, along with their corresponding major gripping members, face opposite directions. Thus, upon positioning of the gripping members in the blocks in the multiple block unit, and upon subsequent lifting of the weight distribution beam, the first major and first series of minor gripping members act in combination with the opposing second major and second series of minor gripping members to exert a clamping force on the interior portion of the center web of each block in the multiple block unit to retain the blocks in alignment for lowering and raising of the multiple block unit.
The mortar applying device includes a mortar applicator, a housing for the mortar applicator, a housing guide and means for controlling the dispensing of mortar onto the top surface of a row of blocks. The housing preferably includes a mortar distribution chamber divided into multiple channels and outer ports to control dispensing of the mortar onto specific portions of the top surface of the row of blocks.
The housing guide preferably comprises a series of wheels attached to the outside of the housing. In a preferred embodiment, the wheels each include a groove positioned in the outer wheel surface to simultaneously traverse a portion of the top surface and a portion of the side surface of the row of blocks. Additionally, the housing preferably includes a handle to permit manual manipulation and movement of the mortar applying apparatus.
The means for controlling dispensing of mortar include a gate covering a portion of the mortar dispensing port and a sensor to facilitate selective application of mortar onto the top surface of the blocks, while substantially limiting application of mortar into the inner cavities of the blocks. The gate is preferably spring-loaded to remain closed under the weight of mortar.
In one preferred embodiment, the sensor comprises a dip sensor pivotally connected to the gate at one end, and pivotally connected to the housing at the other end. The dip sensor includes a dip portion capable of extending below the top block surface to indicate when the mortar applicator is positioned over a block cavity. Contact of the dip sensor with the top surface of the blocks forces the gate open, thus permitting mortar application onto the top surface of the row of blocks.
In another preferred embodiment, the sensor comprises a laser which likewise determines whether the mortar applicator is positioned over a block surface, or over a block cavity. The laser is part of an electronic circuit which controls opening and closing of the gate.
In yet another preferred embodiment, the mortar applying apparatus may be equipped with a laser sensitive indicator to function in combination with a laser to level the course of the apparatus during mortar application.